Observation on the Gametophyte Development of Drynaria roosii Nakaike

The spores of Drynaria roosii Nakaike were cultured in inorganic medium and soil, respectively. The spore germination and gametophyte development were observed under microscope. The results showed that the spores were yellowish, monolete, without perispore and bearing granular ornamentation on the exospore. They are bean-shaped in equatorial view and elliptical in polar view. The spores germinated within 10~12 days after inoculation, the type of germination is Vittaria-type while that of gametophyte development is Drynaria-type. The prothallial plates formed in 20 days after inoculation and the establishment of apical cell was later. After the formation of the prothallial plate, profuse unicellular hairs occurred on both the surfaces and margin of the prothalli. The young prothalli developed in 60 days after inoculation and the mature prothalli are cordate-thalloid. The sex organs formed in 65 days after inoculation. The antheridia appeared about 10 days earlier than archegonia. Archegonial neck usually inclines or curves towards the base of the prothallus at maturity. It could be observed that the embryos break through the archegonia after fertilization.